U.S. patent number 10,192,713 [Application Number 15/542,163] was granted by the patent office on 2019-01-29 for charged particle beam device.
This patent grant is currently assigned to Hitachi High-Technologies Corporation. The grantee listed for this patent is Hitachi High-Technologies Corporation. Invention is credited to Hideki Kikuchi, Naotomo Maruyama, Kiyoshi Yabata.
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United States Patent |
10,192,713 |
Yabata , et al. |
January 29, 2019 |
Charged particle beam device
Abstract
In a side entry type sample holder, vibrations in the radial
direction of the sample holder provoke a resolving power decrease
in the measurement results. In the present invention, the side
entry type sample holder has a stepped portion in the radial
direction of an axial portion. The sample stage has a support part
contacting the stepped portion in a cylindrical portion capable of
moving as one body in the axis direction of the sample holder, and,
through the contact between the stepped portion and the support
part, a frictional force is generated, opposing the radial
direction of the axial portion in the sample holder. In this
manner, the vibrations in the radial direction of the sample holder
are suppressed, and the resolving power decrease in the measurement
results is suppressed.
Inventors: |
Yabata; Kiyoshi (Tokyo,
JP), Kikuchi; Hideki (Tokyo, JP), Maruyama;
Naotomo (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hitachi High-Technologies Corporation |
Minato-ku, Tokyo |
N/A |
JP |
|
|
Assignee: |
Hitachi High-Technologies
Corporation (Tokyo, JP)
|
Family
ID: |
56405589 |
Appl.
No.: |
15/542,163 |
Filed: |
December 7, 2015 |
PCT
Filed: |
December 07, 2015 |
PCT No.: |
PCT/JP2015/084230 |
371(c)(1),(2),(4) Date: |
July 07, 2017 |
PCT
Pub. No.: |
WO2016/114033 |
PCT
Pub. Date: |
July 21, 2016 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
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US 20180269027 A1 |
Sep 20, 2018 |
|
Foreign Application Priority Data
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|
|
|
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Jan 13, 2015 [JP] |
|
|
2015-003787 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J
37/20 (20130101); H01J 37/26 (20130101); H01J
2237/2007 (20130101); H01J 2237/204 (20130101); H01J
2237/0216 (20130101) |
Current International
Class: |
H01J
37/20 (20060101); H01J 37/26 (20060101) |
Field of
Search: |
;250/440.11,441.11,442.11,443.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
56-15567 |
|
Feb 1981 |
|
JP |
|
1-129754 |
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Sep 1989 |
|
JP |
|
2010-157491 |
|
Jul 2010 |
|
JP |
|
2014-38786 |
|
Feb 2014 |
|
JP |
|
2014-89936 |
|
May 2014 |
|
JP |
|
Other References
International Search Report (PCT/ISA/210) issued in PCT Application
No. PCT/JP2015/084230 dated Mar. 15, 2016 with English-language
translation (four (4) pages). cited by applicant .
Japanese-language Written Opinion (PCT/ISA/237) issued in PCT
Application No. PCT/JP2015/084230 dated Mar. 15, 2016 (three (3)
pages). cited by applicant.
|
Primary Examiner: Ippolito; Nicole
Attorney, Agent or Firm: Crowell & Moring LLP
Claims
The invention claimed is:
1. A charged particle beam apparatus comprising: a sample holder
configured to hold a sample; and a sample stage into which the
sample holder is introduced, wherein the sample holder includes: a
shaft portion configured to hold a sample base on which a sample is
placed on one end portion; a step portion configured to he formed
in a radial direction of the shaft portion; and an elastic body
configured to be arranged in a vicinity of the step portion, the
sample stage includes: a cylindrical portion configured to be
capable of accommodation of a part of the shaft portion; an outer
cylindrical portion configured to accommodate the cylindrical
portion; and a guide portion configured to be arranged between the
cylindrical portion and the outer cylindrical portion, the guide
portion including a ball member configured to be capable of
rotation in an axial direction of the shaft portion, the guide
portion supporting the cylindrical portion in the radial direction
of the shaft portion, the cylindrical portion forms a support
portion configured to contact the step portion when the sample
holder is inserted, and contact between the step portion and a
support portion generates a frictional force in the radial
direction of the shaft portion relative to the sample holder.
2. The charged particle beam apparatus according to claim 1,
wherein the step portion includes a recessed structure and the
support portion includes a protrusion structure, so that they are
formed to fit to each other.
3. The charged particle beam apparatus according to claim 1,
wherein the step portion includes a protrusion structure and the
support portion includes a recessed structure, so that they are
formed to fit to each other.
4. The charged particle beam apparatus according to claim 1,
wherein the sample holder includes: apart from the step portion
configured to be formed in a radial direction of the shaft portion,
a second step portion configured to be formed on a side of the
sample base from the step portion and in the radial direction of
the shaft portion, and the sample stage includes: a second support
portion configured to contact the second step portion when the
sample holder is inserted.
5. The charged particle beam apparatus according to claim 1,
wherein the support portion is formed of sapphire.
6. The charged particle beam apparatus according to claim 1,
wherein the guide portion includes two or more rows of ball members
configured to be arranged parallel to an axial direction of a shaft
portion of the sample holder.
7. The charged particle beam apparatus according to claim 1,
wherein a side of the sample base from a contact portion between
the support portion and the step portion is maintained in a vacuum
state.
8. A sample stage for a charged particle beam apparatus into which
a sample holder configured to hold a sample is introduced, the
sample holder comprising: a shaft portion configured to hold a
sample base on which a sample is placed on one end portion; a step
portion configured to be formed in a radial direction of the shaft
portion; and an elastic body configured to be arranged in a.
vicinity of the step portion, the sample stage comprising: a
cylindrical portion configured to be capable of accommodation of a
part of the shaft portion; an outer cylindrical portion configured
to accommodate the cylindrical portion; and a guide portion
configured to be arranged between the cylindrical portion and the
outer cylindrical portion, the guide portion including a ball
member configured to be capable of rotation in an axial direction
of the shaft portion, the guide portion supporting the cylindrical
portion in the radial direction of the shaft portion, wherein the
cylindrical portion forms a support portion configured to contact
the step portion when the sample holder is inserted, and contact
between the step portion and a support portion generates a
frictional force in the radial direction of the shaft portion
relative to the sample holder.
Description
TECHNICAL FIELD
The present invention relates to a charged particle beam apparatus,
and more particularly to a charged particle beam apparatus provided
with a sample stage into which a side-entry sample holder is
introduced.
BACKGROUND ART
A charged particle beam apparatus, e.g., an electron microscope
typified by a transmission electron microscope (Transmission
Electron Microscope, TEM) adopts a side-entry sample stage into
which a sample holder is introduced in a traverse direction
relative to a mirror body.
PTL 1 relates to a side-entry sample stage. PTL 1 describes a
structure including: a slider tube that slides in a longitudinal
direction of the sample holder and can move together with the
sample holder; a touching member that contacts the slider tube and
determines an setting position of the sample holder; and an elastic
body arranged between the slider tube and the touching member. The
structure is for reducing sample drift due to distortion of an
O-ring that seals between a vacuum sample chamber and the
atmosphere in a sample holder.
CITATION LIST
Patent Literature
PTL 1 : JP Patent Publication (Kokai) 2014-38786 A
SUMMARY OF INVENTION
Technical Problem
An electron microscope, e.g., a TEM, performs observation under
high magnification conditions for direct observation of atoms, and
there is an increasing need for high resolution. Under such
observation conditions, however, a subtle displacement of a sample
can greatly influence a resulting image. In particular, in the case
of a side-entry sample stage, when a sample holder is introduced or
moved, oscillations occur in a radial direction of the sample
holder, i.e., in a direction perpendicular to a longitudinal
direction (axial direction). A resulting image is deteriorated with
an increase in the amplitude (displacement amplitude), rendering
high-precision sample observation difficult.
With the technique disclosed in PTL 1 , the sample holder is
temporarily positioned by the touching member, and then the sample
holder is pushed back by the spring force of the elastic body to a
position that is determined as a final position of the sample
holder, thereby reducing sample drift. However, there is no
consideration with regard to oscillations in a radial direction of
the sample holder described above.
An object of the present invention relates particularly to a
reduction in displacement amplitude due to oscillations in a radial
direction of a sample holder to achieve high-resolution sample
observation in a side-entry sample stage.
Solution to Problem
An aspect to achieve the above object is a charged particle beam
apparatus including: a sample holder configured to hold a sample;
and a sample stage into which the sample holder is introduced,
wherein the sample holder includes: a shaft portion configured to
hold a sample base on which a sample is placed on one end portion;
a step portion configured to be formed in a radial direction of the
shaft portion; and an elastic body configured to be arranged in a
vicinity of the step portion, the sample stage includes: a
cylindrical portion configured to be capable of accommodation of a
part of the shaft portion; an outer cylindrical portion configured
to accommodate the cylindrical portion; and a guide portion
configured to be arranged between the cylindrical portion and the
outer cylindrical portion, the guide portion including a ball
member configured to be capable of rotation in an axial direction
of the shaft portion, the guide portion supporting the cylindrical
portion in the radial direction of the shaft portion, the
cylindrical portion forms a support portion configured to contact
the step portion when the sample holder is inserted, and contact
between the step portion and a support portion generates a
frictional force in the radial direction of the shaft portion
relative to the sample holder.
Advantageous Effects of Invention
The aforementioned configuration reduces displacement amplitude due
to oscillations of a sample holder in a side-entry sample stage and
contributes to high-resolution observation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a view illustrating a basic configuration of a charged
particle beam apparatus according to the present embodiment.
FIG. 2 is a view illustrating a cross-section in an x-z plane when
a sample holder is inserted into a sample stage according to the
present embodiment (first embodiment).
FIG. 3 is a view illustrating a cross-section in an x-z plane in a
state where a sample holder is inserted into a sample stage
according to the present embodiment (first embodiment).
FIG. 4 is a view illustrating a cross-section in an x-y plane in a
state where a sample holder is inserted into a sample stage
according to the present embodiment (first embodiment).
FIG. 5 is a view illustrating an enlarged cross-section in an x-y
plane of an axial support portion of a sample holder and a first
step portion of a sample stage according to the present embodiment
(second embodiment).
FIG. 6 is a view illustrating a cross-section in an x-y plane in a
state where a sample holder is inserted into a sample stage
according to the present embodiment (third embodiment).
FIG. 7 is an illustrative view describing introduction of a sample
holder into a sample stage according to the present
embodiments.
FIG. 8 is a view illustrating a basic configuration of a
cross-section of a sample holder during sample observation
according to the present embodiments.
FIG. 9 is a view describing displacement amplitude in a radial
direction of a side-entry sample holder.
DESCRIPTION OF EMBODIMENTS
The present embodiments are described below in conjunction with the
drawings. Like constituent parts in the drawings are designated
with like reference numerals throughout, and the description may be
omitted.
<Apparatus configuration>
FIG. 1 illustrates a basic configurational view of a TEM, which is
an example of a charged particle beam apparatus according to the
present embodiments.
A TEM body 100 is mainly comprised of an electron gun 101, an
illumination lens 103, an objective lens 107, a projection lens
108, a sample chamber 111, and a detector 109, and is accommodated
in a column 112. A sample 106 is attached to a sample holder 105.
The sample holder 105 is introduced into the sample chamber 111
from a sample stage 104, which is provided on a side surface of the
TEM body 100. The sample chamber 111 is a space indicated by the
dotted lines in the drawing and is vacuum-evacuated with a vacuum
pump, which is not illustrated, during sample observation so as to
be maintained in a vacuum state (e.g., about 10.sup.-5 Pa). In the
drawing, the sample chamber 111 is located in a space below the
illumination lens 103 and above the projection lens 108, but is not
limited thereto. The detector 109 is provided below the projection
lens 108. In the drawing, a controller 110 is connected to each
component to generally control the apparatus. However, it may be
configured to include controllers that are independent of one
another for the respective components.
An electron beam 102 emitted from the electron gun 101 is focused
by the illumination lens 103, and the sample 106 mounted on the
sample holder 105 in the sample chamber 111 is illuminated. An
electron that has transmitted through the sample 106 forms an image
through the objective lens 107, and the image is enlarged by the
projection lens 108 and the image is projected on the detector 109.
The projected image is displayed by an output device, which is not
illustrated, via the controller 110.
FIG. 7 is a view describing introduction of the sample holder into
the sample stage according to the present embodiments.
The sample holder 105 is inserted, from the side of a holder end
portion 105a, into the sample stage 104. The sample stage 104 is
provided on a side surface of the TEM body 100.
FIG. 8 is a view illustrating a basic configuration of a
cross-section of the sample holder during sample observation
according to the present embodiments.
The sample 106 placed on a sample base 211 at the holder end
portion 105a of the sample holder 105 is arranged to be located
below the electron gun 101 during observation. The sample 106 is
observed by an electron beam emitted from the electron gun 101.
Regarding the sample holder 105, the sample base 211 can be
inclined with a sample inclination mechanism, which is not
illustrated, so that the sample 106 can be observed at any
angle.
First Embodiment
<Configuration and operation of the sample stage and the sample
holder>
Next, a configuration and operation of the sample stage and the
sample holder according to the present embodiment are described in
conjunction with FIGS. 2 to 4.
FIG. 2 is a view illustrating a cross-section in an x-z plane when
the sample holder is inserted into the sample stage according to
the present embodiment.
The sample stage 104 is mainly comprised of an outer cylinder 201,
a cylindrical member 202, a bellows 203, a guide portion 204, and
an actuator 205. The cylindrical member 202 includes a holder axial
support portion 213 and an actuator axial support portion 207,
which will be described later. The guide portion (linear-motion
bearing portion) 204 fixed to the outer cylinder 201 supports the
cylindrical member 202 in a radial direction of the sample holder
105 together with the ball member 206, which is rotationally
movable in an axial direction of the sample holder 105. The bellows
203 connects the outer cylinder 201 and the cylindrical member 202
in an axial direction of the sample holder 105 in an airtight
manner. The actuator 205 is arranged on the outer cylinder 201 and
is arranged to closely attach to the actuator axial support portion
207 of the cylindrical member 202.
The sample holder 105 is mainly comprised of a large-diameter
portion 208, a small-diameter portion 209, a first step portion
210, a second step portion 216, the holder end portion 105a, and
the sample base 211. An elastic body 212 is provided in the
vicinity of the first step portion 210. The elastic body 212 is
arranged between the sample holder 105 and an inner wall of the
cylindrical member 202. Examples of the elastic body 212 include an
O-ring formed of a material, e.g., rubber, which is foamed to
provide airtightness as well as stiffness in a radial direction of
the sample holder 105. The holder end portion 105a indicates a
region located on the sample base 211 side from the second step
portion 216, and the small-diameter portion 209 indicates a region
located between the first step portion 210 and the second step
portion 216. The large-diameter portion 208 indicates a region
located on a root side from the first step portion 210, i.e.,
opposite the sample base 211 side. The sample holder 105 is
inserted with the elastic body 212 contacting an inner wall of the
cylindrical member 202 of the sample stage 104, and is moved to a
position where the first step portion 210 of the sample holder 105
comes into contact with the holder axial support portion 213 of the
cylindrical member 202. The sample holder 105 inserted has two
ends, which are supported by a holder end support portion 214 and a
holder root support portion 215 of the outer cylinder 201,
respectively.
In a state being inserted into the sample stage 104, the sample
holder 105 is on a boundary indicated by the dotted line in the
drawing, specifically such that the holder end portion 105a side
from the elastic body 212 is vacuum and the opposite side is
exposed to the atmosphere. The sample holder 105 is subjected to a
force that is proportional to an area of the large-diameter portion
208 and moves the holder axial support portion 213 in a +x
direction indicated in the upper right graph of the drawing. The
actuator 205 moves and supports the cylindrical member 202 in an
axial direction via an axial reception portion 207. Thus, the first
step portion 210 is closely attached and supported by a force that
is generated with respect to the holder axial support portion 213
and acts in an axial direction of the sample holder 105.
Furthermore, the holder axial support portion 213 and the first
step portion 210 generate a frictional force in a radial direction
because of a force (normal reaction) acting in an axial direction
of the sample holder 105. Therefore, in a state where the sample
106 is observed at rest in a charged particle beam apparatus, the
holder axial support portion 213 and the first step portion 210 are
fixed by the frictional force and no slipping occurs in a radial
direction. When the sample 106 is set in an illumination position
of the electron beam 102 as illustrated in FIG. 3, the holder axial
support portion 213 also radially supports the first step portion
210.
Next, operation in an axial direction of the sample holder 105 is
described. The actuator axial support portion 207 is pressed and
moved in the -x direction indicated in the upper right graph of the
drawing by the operation of the actuator 205, the cylindrical
member 202 is moved in the same direction, and the sample holder
105, which is supported by the axial support portion 213 of the
cylindrical member 202 is also moved in the same direction. When
the actuator 205 is operated in the .+-.x direction indicated in
the upper right graph of the drawing, the sample holder 105 and the
cylindrical member 202 subjected to the force in the +x direction
are collectively moved in the +x direction.
FIG. 3 is a view illustrating a cross-section in an x-z plane in a
state where the sample holder is inserted into the sample stage
according to the present embodiment. In addition, FIG. 4 is a view
illustrating a cross-section in an x-y plane in a state where the
sample holder is inserted into the sample stage according to the
present embodiment. When the actuator 205 is operated in the -x
direction of the upper right of the drawing to move the position of
the sample 106, the cylindrical member 202 is pressed in the same
direction and is subjected to a force couple around a y direction.
At this time, the guide portion 204 supports the outer
circumference of the cylindrical member 202 with the ball member
206 formed around in the x direction twice or more (fifth in the
present drawing) to prevent the rotation of the cylindrical member
202 along the y direction. With the above configuration, the sample
holder 105, which moves together with the cylindrical member 202,
can also be prevented from rotating along the y direction.
<Reduction in displacement amplitude>
Next, a reduction in displacement amplitude in a radial direction
of the sample holder by means of the configurations of the sample
stage and the sample holder described above is described in
conjunction with FIG. 9.
FIG. 9 is a view describing displacement amplitude in a radial
direction of a side-entry sample holder.
In the case of a side-entry sample stage into which a sample holder
905 is inserted from an atmospheric side into a vacuum, it is
required that a sample be arranged at an end of the sample holder
905 and a sample base placed on a holder end portion 905a of the
sample holder 905 be moved to and set at an illumination position
of an electron beam. Because the interior of the charged particle
beam apparatus is in a vacuum state, it is required to have a small
airtight area so that the sample base reaches a central position of
a TEM column, which is an illumination position of the electron
beam, from the outside of the charged particle beam apparatus.
Therefore, the sample holder 905 is desirably formed in a long
rod-like shape. For this reason, the sample holder 905, which is
formed to have a rod-like shape, tends to displace in a radial
direction as illustrated in FIG. 9, resulting in an increase in
amplitude of the displacement. Therefore, in order to reduce the
displacement amplitude at both ends for stable positioning of the
sample, support is preferably provided in the vicinity of both
ends. Displacement amplitude refers to a width obtained when the
sample holder 905 is displaced in a radial direction.
However, it has been revealed by results of research by the
inventors that, when the sample holder 905 has a long axial length,
even a structure that supports both ends increases the displacement
amplitude.
Therefore, in the present embodiment, as described in FIGS. 2 to 4,
the guide portion 204 is fixedly arranged between the outer
cylinder 201 and the cylindrical member 202. The guide portion 204
supports the cylindrical member 202 in a radial direction of the
sample holder 105 via the ball member 206. The guide portion 204 is
desirably positioned in the vicinity of the holder axial support
portion 213 of the cylindrical member 202. When the sample holder
105 is inserted into the sample stage 104 and the sample 106 is
moved to an illumination position of the electron beam 102, the
holder axial support portion 213 of the cylindrical member 202 and
the first step portion 210 of the sample holder 105 are arranged in
a contact state in an axial direction. At this time, a frictional
force is generated between the holder axial support portion 213 and
the first step portion 210. Therefore, slipping does not occur in a
radial direction of the sample holder 105, enabling stable
support.
Furthermore, at this time, the position of the sample holder 105 in
a radial direction is determined by the holder end support portion
214 and the holder root support portion 215. As described above,
the frictional force generated due to the contact between the
holder axial support portion 213 and the first step portion 210
also enables a reduction in misalignment.
According to the present embodiment, the axial support portion 213
has an annular structure to evenly contact the first step portion
210. However, other than the above, for example, a plurality of
projection structures having a roughly hemispherical shape may be
arranged. When the sample base 211 is moved in the x and y
directions in a state where the sample 106 on the sample base 211
is illuminated with the electron beam 102 of the charged particle
beam apparatus in the z direction indicated in the upper right
graphs of FIGS. 2 and 3, disturbance tends to occur in a resulting
image. Therefore, when the projection structures are provided, the
projection structures are desirably arranged on the holder axial
support portion 213 at symmetrical intervals relative to an axial
direction of the sample holder 105. Furthermore, in the present
embodiment, a protrusion portion is provided on the holder axial
support portion 213; however, a protrusion portion may be provided
on the first step portion 210 side.
In addition, in the aforementioned form, the first step portion 210
of the sample holder 105 is provided at a roughly middle position
in an axial direction. When both ends are supported in the
structure in which the sample holder 105 is formed in a rod shape,
the displacement amplitude tends to increase at a roughly middle
position in an axial direction. Therefore, the sample holder 105 is
desirably supported at a roughly middle position in an axial
direction. However, the sample holder 105 may be supported at a
different position in an axial direction between both ends. Such a
configuration can also reduce oscillations in a radial direction of
the sample holder 105.
In addition, the present embodiment describes a case where the
material of the holder axial support portion 213 is the same as the
material of the cylindrical member 202. However, a hard material,
e.g., sapphire, may be used. In that case, the material of the
first step portion 210 of the sample holder 105 may be titanium or
the like to have an increased friction coefficient. Therefore, even
when an exciting force on the sample holder 105 is increased, the
axial support portion 213 can stably support the first step portion
210.
In addition, when the axial support portion 213 includes the
protrusion structures with respect to the first step portion 210,
contact with the protrusion structures can deform the first step
portion 210. In that case, the axial support portion 213 has a
plane surface or, as will be described later in the second
embodiment, the first step portion 210 includes a recessed
structure. Thus, when the axial support portion 213 and the first
step portion 210 contact to be closely attached in an axial
direction, the first step portion 210 is not deformed and a
frictional force is generated between the first step portion 210
and the cylindrical member 202, so that the sample holder 105 can
be maintained in a state where slipping hardly occurs in a radial
direction. Thus, the sample holder 105 can be stably supported
axially and radially without deformation of the first step portion
210 by the axial support portion 213.
<Reduction in sample drift>
Sample drift is a phenomenon that the position of the sample base
211 or the illumination position of the electron beam 102 on the
sample 106 varies with various factors including deformation of a
component of the charged particle beam apparatus and temperature
changes. In the case of the side-entry sample stage 104, when a
component, e.g., the elastic body 212, is deformed by the movement
of the sample holder 105, a restoring force is generated to restore
from the deformation, resulting in sample drift. In the present
embodiment, since the sample holder 105 and the cylindrical member
202 can be moved collectively, the elastic body 212 is not
deformed, and sample drift can be reduced in addition to the
reduction in displacement amplitude described above.
Second Embodiment
In the present embodiment, a structure in which the holder axial
support portion 213 of the cylindrical member 202 of the sample
stage 104 and the first step portion 210 of the sample holder 105
are fit by means of a recess and a protrusion is described in
conjunction with FIG. 5.
FIG. 5 is a view illustrating an enlarged cross-section in an x-y
plane of the first step portion 210 of the sample stage according
to the present embodiment. It is an enlarged view of Region A of
the sample holder 105 indicated by the dotted line indicated at the
upper left of the drawing. The present configuration is different
in that the first step portion 210 of the sample holder 105
indicated in the first embodiment is further formed with a recessed
portion. For the other configurations having the same functions as
the configurations described above in the first embodiment, the
description may be omitted. The sample holder 105 is subjected to a
force in the +x direction, and then the first step portion 210,
which forms the recessed portion, and the cylindrical member 202
are closely attached in an axial direction of the sample holder
105. At this time, the first step portion 210, which forms the
recessed portion, and the axial support portion 213, which forms
the protrusion portion, are configured to engage with each other,
and have a portion at which they contact with each other in a
radial direction in addition to an axial direction of the sample
holder 105. Therefore, the sample holder 105 is stably supported at
the holder axial support portion 213. Thus, the fitting between the
recessed portion, which is formed on the first step portion 210,
and the protrusion portion, which is formed on the holder axial
support portion 213, increases the contact area in a radial
direction of the sample holder 105, thereby enabling an increase in
contact stiffness. Therefore, even when a force greater than the
frictional force generated between the recessed portion, which is
formed on the first step portion 210, and the protrusion portion,
which is formed on the axial support portion 213, is applied, a
state in which they do not slip with respect to each other in a
radial direction of the sample holder 105 can be maintained.
Third Embodiment
The present embodiment describes a structure in conjunction with
FIG. 6 in which, in addition to the aforementioned configuration,
the sample stage 104 further includes a second holder axial support
portion 218 and the sample holder 105 further includes a third step
portion 217. As described above, the present configuration is
different in that the sample holder 105 indicated in the first
embodiment further includes the third step portion 217 and the
sample stage 104 includes the second holder axial support portion
218.
For the other configurations having the same functions as the
configurations described above in the first embodiment, the
description may be omitted.
The sample holder 105 is mainly comprised of the large-diameter
portion 208, a middle-diameter portion 219, the small-diameter
portion 209, the holder end portion 105a, the sample base 211, the
first step portion 210, the second step portion 216, and the third
step portion 217. An elastic member 220 is provided in the vicinity
of the third step portion 217. The elastic member 220 has a disk
shape.
As described above, when the sample holder 105 is inserted into the
sample stage 104, because the interior of the charged particle beam
apparatus is in a vacuum state, the sample holder 105 is subjected
to a force in the +x direction, and the first step portion 210 and
the axial support portion 213 of the cylindrical member 202 are
closely attached and hardly slip in a radial direction because of
the frictional force, so that the sample holder 105 is stably
supported axially and radially.
The outer cylinder 201 of the sample stage 104 includes the second
holder axial support portion 218 and the elastic member 220. The
second holder axial support portion 218 is arranged at an end of
the elastic member 220. During insertion into the sample stage 104,
when the sample holder 105 is subjected to a force in the +x
direction, the third step portion 217 and the second holder axial
support portion 218 contact in a closely attached manner.
The elastic member 220 is formed of a structure having a low
stiffness in an axial direction of the sample holder 105 and has a
high stiffness in a radial direction, e.g., rubber. The sample
holder 105 hardly slips in a radial direction because of the
frictional force, enabling more stable support.
Next, operation in an axial direction of the sample holder 105 is
described. When the cylindrical member 202 is moved in the -x
direction by the operation of the actuator 205, the sample holder
105 supported by the cylindrical member 202 is also moved in the
same -x direction together. The elastic member 220, when inserted,
is arranged to generate a force in the -x direction. The second
holder axial support portion 218, which is arranged at an end of
the elastic member 220, follows the sample holder 105 and is moved
in a state being closely attached to the third step portion
217.
When the actuator 205 is operated in the +x direction, because the
interior of the charged particle beam apparatus is in a vacuum
state, the sample holder 105 subjected to a force in the +x
direction is moved in the +x direction together with the
cylindrical member 202. At this time, even when the sample holder
105 is moved in the +x direction, because a reaction force
generated by the deformation of the elastic member 220 is small,
the second holder axial support portion 218 follows the motion of
the sample holder 105 and is moved while being closely attached to
the third step portion 217.
With the configuration described above, the sample holder 105 can
be supported in a radial direction with a higher stiffness than
that of the case where the number of axial support portion is one,
enabling a more effective reduction in displacement amplitude of
the sample holder 105. In the present embodiment, the configuration
including two axial support portions is described. However, three
or more axial support portions may be provided. The present
embodiments are not limited to the aforementioned configurations,
but various variations may be included. For example, the
aforementioned embodiments are described in detail for the sake of
comprehensible description and are not necessarily limited to
include all the described configurations. In addition, a part of
the configuration of a certain embodiment may be replaced with a
configuration of a different embodiment, and a configuration of a
different embodiment may be added to the configuration of a certain
embodiment. In addition, a different configuration may be added,
deleted, or replaced with respect to a part of the configurations
of the embodiments.
REFERENCE SIGNS LIST
100 TEM body 101 electron gun 102 electron beam 103 illumination
lens 104 sample stage 105, 905 sample holder 105a, 905a holder end
portion 106 sample 107 objective lens 108 projection lens 109
detector 110 controller 111 sample chamber 112 column 201 outer
cylinder 202 cylindrical member 203 bellows 204 guide portion 205
actuator 206 ball member 207 actuator axial support portion 208
large-diameter portion 209 small-diameter portion 210 first step
portion 211 sample base 212 elastic body 213 holder axial support
portion 214 holder end support portion 215 holder root support
portion 216 second step portion 217 third step portion 218 second
axial support portion 219 middle-diameter portion 220 elastic
member
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